feat(transaction-pay): add ordered strategy fallback orchestration

[pedronfigueiredo]

Explanation

As per preemptive validation on #7806

• Adds ordered strategy retrieval via TransactionPayController:getStrategies while preserving existing getStrategy behavior.
• Adds compatibility filtering (supports(...)) during strategy selection.
• Implements quote fallback orchestration:
  • try next strategy when quote retrieval fails
  • try next strategy when quote list is empty
  • skip unsupported strategies
• Implements publish-hook fallback orchestration:
  • execute primary strategy from existing quote strategy
  • on execution failure, rebuild quote requests and try next compatible strategy
  • throw original primary error if all fallback attempts fail

References

Addresses https://github.com/MetaMask/MetaMask-planning/issues/6992

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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Note

Medium Risk
Changes core quote-selection and submission routing for pay transactions; incorrect strategy ordering, supports checks, or fallback behavior could alter fees/quotes returned or cause pay flows to fail in edge cases.

Overview
MetaMask Pay now supports ordered strategy orchestration with fallback. TransactionPayController accepts an optional getStrategies callback (while preserving getStrategy) and falls back to a remotely-configured strategyOrder feature flag (defaulting to Relay), filtering invalid values.

Quote updates/refresh now try strategies in priority order via getStrategiesByName, optionally skip incompatible strategies via a new PayStrategy.supports(...) hook, and fall through when a strategy errors, returns no quotes, or fails batch-transaction generation. Publish-time submission now selects the strategy from quotes[0].strategy (instead of re-resolving from controller) to ensure the submit path matches the quote origin.

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[cursor]

Source amounts strategy mismatch with fallback strategy selection

Medium Severity

The updateSourceAmounts call in #updateTransactionData uses getStrategy (returning the first strategy) to decide whether same-token quotes are required via isQuoteAlwaysRequired. But the new fallback loop in getQuotes may select a different strategy. For a Hyperliquid USDC deposit where the payment token matches the required token, if Bridge is first in the order, isQuoteAlwaysRequired returns false, the source amount is skipped, and no quote requests are built — so even when Relay (which does need that quote) is tried as fallback, requests is already empty and getQuotes returns early with no quotes.

Additional Locations (1)

• packages/transaction-pay-controller/src/TransactionPayController.ts#L159-L174

 

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Cursor Bugbot has reviewed your changes and found 1 potential issue.